Asymptotic Symmetries: from Concepts to Observations

ended

At its core, Nature is described by gauge systems such as electrodynamics and gravitation. Such theories are written in terms of redundant quantum fields, but it was recently realized that some of these redundancies are, in fact, genuine symmetries. The corresponding transformations are known as asymptotic symmetries, a prominent example of which is the intriguing Bondi-Metzner-Sachs (BMS) group relevant to gravitational radiation. Accordingly, the purpose of this project is to study asymptotic symmetries along three axes. Firstly, look for their experimental signatures, such as memory effects or Berry phases. The latter are uncharted territory, so many of their aspects remain to be clarified; besides, their scope goes well beyond high-energy physics, as analogous phases exist in shallow water dynamics. Secondly, address the conceptual issue of field-dependent central charges occurring in asymptotic symmetry algebras of various gauge systems; this feature is radically new for symmetries in Nature, and has the potential to overturn many of our preconceptions about symmetries in general. Thirdly, relate representations of asymptotic symmetry algebras to Faddeev-Kulish dressing; this reformulation would open the door to countless applications and to a conceptual leap in our understanding of both particles physics and quantum gravity.